Objective: The NCI Challenge Goal 2015 is to eliminate suffering due to cancer. Radiotherapy induced skin toxicity has significant adverse effects on multiple dimensions of breast cancer patients' quality of life. The long- term objective of this Career Development Award proposal is consistent with the NCI Challenge Goal in two ways: 1) providing the necessary training for the candidate to become an independent cancer prevention and control researcher specializing in the effects of radiotherapy on patients' quality of life; and 2) to develop and test a cognitive-behavioral intervention to combat the effects of acute skin toxicity on breast cancer radiotherapy patients' quality of life (QOL). Specific Aims: 1) To use qualitative research methods to thoroughly assess and document the effects of radiotherapy-induced skin toxicity on quality of life of breast cancer radiotherapy patients. 2) To investigate the impact of a behavioral medicine intervention, including cognitive-behavioral therapy and hypnosis (CBT+H), informed by the results of Aim 1, on the effects of skin toxicity in breast cancer radiotherapy patients. 3) To explore the role of social and psychological factors in the mediation and moderation of the beneficial impact of the CBT+Hypnosis intervention. Key mediators and moderators include: social factors (working alliance, interpersonal complementarity), psychological factors (distress, response expectancies) and hypnotizability. Research Design and Methods: Aim 1: Breast cancer radiotherapy patients (N=20) will participate in individual qualitative interviews and focus groups to learn how skin toxicity has affected their QOL. Thematic and discursive analytic approaches will be used. Aims 2 and 3 will be carried out using RCT methodology to compare a cognitive-behavioral intervention with hypnosis (CBT+H) to attention control (AC) with regard to improvements in skin toxicity-related QOL. 144 breast cancer radiotherapy patients will be randomly assigned to group, and assessments will be administered during, and for one month following, radiotherapy. Public Health Relevance: First, the award will produce a highly qualified cancer prevention and control researcher with a focus on radiotherapy. Second, the proposal will test a new intervention with the potential to improve the quality of life of all breast cancer patients undergoing radiotherapy, an often ignored group from the behavioral medicine perspective.